Difference between QA and QC
As we've talked in a previous post about the Definition of Quality, with these 2 terms exist the same “issue” where every single person/organization defines Quality Assurance (QA) and Quality Control (QC) in a bit different way. Also, many people including HHRR (Human Resources) and quality professionals do not know what QA and QC really means, and what the difference is between both terms. For those reasons, these concepts are often used interchangeably, and in some organizations one department performs the activities of both.

The truth is that both terms have strong interdependence; QA relies mostly on the QC feedback and both work to deliver good quality products/services; but they are different processes.

Next table shows the differences between them.

QA vs. QC
Definition from ASQ.org
Assurance: The act of giving confidence, the state of being certain or the act of making certain.

QA: The planned and systematic activities implemented in a quality system so that quality requirements for a product or service will be fulfilled.

Other definition

QA is a failure prevention system that predicts almost everything about product safety, quality standards and legality that could possibly go wrong, and then takes steps to control and prevent flawed products or services from reaching the advanced stages of the supply chain. Definition from ASQ.org
Control: An evaluation to indicate needed corrective responses; the act of guiding a process in which variability is attributable to a constant system of chance causes.

QC: The observation techniques and activities used to fulfill requirements for quality.

Other definition

QC is a failure detection system that uses a testing technique to identify errors or flaws in products and tests the end products at specified intervals, to ensure that the products or services